Cumulative stand-by power consumption of different electrical devices in homes and in industry is huge. Thus, there is a large energy savings potential by reducing this electrical consumption to the lowest level. For example a DVD player or a Set-Top Box generally consumes 1 to 4 Watts in its Stand-by mode, resulting in an annual energy consumption of 8 to 30 kWh.
In known electrical installations or devices equipped with a voltage converter and having a stand-by mode, the main problem relative to the power consumption in the stand-by mode are due to the fact that the converter remains powered in this stand-by mode, i.e. that the secondary side of this converter is still supplied by the primary side. Thus, the secondary supply lines are still active as power sources for the several elements and units on the secondary side of the installation or device.
Even if a power management unit is arranged on the secondary side to switch OFF some units and/or to put some units into a low energy consumption mode, in particular a main CPU (Central Processing Unit), the converter is ON and the energy losses of this converter are continuously present in the stand-by mode. Furthermore, some units or elements on the secondary side continue to consume energy in the stand-by mode because they are powered.